Im provem ent in locomotive-lam ps



N .e J. KN APP. LoeoMoTIvE LAMP.

Patented Sept. 13, 1859.

UNITED SfmtTESS.,PATENT,

.NE'LsoN J.' KNAPizoren-ionen), lILLfNoLs.

lMPR-Q'vl-:MENT' |N LoeomolTlve-LAMPS.

Specification forming partof Letters Patent No. 25,421, dated September 13, 1859.

To all whom it 77mg concern;`

3e it known that I, NELSON J. KNAPP, of Chicago, inthe `coun'ty'oi` Cook and State ol' Illinois, have invented a new and Improved Lamp for Locomotives; Ships, &e.;:and-I do hereby declare that the ollowing is a full, clear, and exact description of thesame, vreference being had tothe accompanying drawings, making av part 'of this specification, in. whichf v e Figure 1 -is a longitudinal vertical section Of' my invention, -ta-ken in thelinea: of. Fig. 2. -I ig.' 2 is a transverse vertical section ot' the same in the lineg/ g/.of Fig. l. lSimilar letters of reference indicate corresponding parts in the two iigures.- f This invention Aconsist-s in, combining an ellipsoidal and 'a 'paraboloidal reflector, as herei n afterfully show nlant described, 'Whereby I am enabled to use alaigeliame and have the rays .of llight Whiohissue therefrom project'ed parallelly withi-nihef-limited dimenf sions required, in order to receive the full .bent.thereof. f

In locomotive lamps, f commonly .termed head-lamps, which are placed on the front part of the locomotive, in order to throw light on the track, aparaboloidal reileetoris used, in order that the reflectedrays' maybe proljected parallelly, and, so far Yas possible, kept Within a space-.equal in-width-to the track., In order, however, to carry out this plan. the flame of the lamp ismeeessarily placed at the focus of a paraboloid, and-as the focus of a parabolo'id of sufcient'dimensions to keep the rays of light Within a compass equal to the width of the track is quite near the back end 'of the paraboloid a'iiaine of quite limited size can only be used.

B my invention, as previously stated, I- am enabled to use a large flame and throw a more brilliant vand intense `light enfthe track at a greaterdistance than usual. The

invention is applicable to ships, and also may beused forsignal-Hghts, &c. n Q To enable those skilled in the artto fully ,understand and construct my invent-ion, l will proceed to describe it. A represents the case otjja lamp, which may .be constructed of sheet metal, and B represents a slide, which is fitl'edin the bottonr of theback part of the case and allowed n to slide transversely in and out from the To this side B the usual Argand burner C and fornita-in rD are attached.

^ E is an ellipsoidal reflector, Whiclris placed Within the ease A. Onehalf (l. of this retleoty or is attached to the slide B, and the burner C 'is placed'within it at its focus b. The

other half o is secured permanently within the case and has 'a paraboloidahre'liector l) attached to its outer end.` The p art cof the ellipsoidal reiiectorE and the paraboloidal reflector. D havea common focus d, as shownv .clearly in Fig. l. The reflector-SE D may be constructed of. any of the materials used, for suclrpurpose, and the outer end of the' re- [lect-or l) is covered hy a glass F and is flush in Fig. ll.

From the above description of parts it will be seen'that all the rays of, ligllt. from the flame e, which is at the focus-1f, that are' rewith the end of th'e case'A, as shown clearlyv ileeted from the ellipsoid E will pass through theother focus d of the ellipsoid, and as the focus (l is common to both the ellipsoid' E and paraboloid D the rays reflected from E and cast against the inner side of l) will be re .iiected therefrom -in parallel rays, as shown in Fig.' 1. The features of the ellipsoid and paraboloid are well known, and lthere/fore do not require any particular' elucdatiou. The foci of the ellipsoid` E are at some distance from its ends; but the focus ot! the paraboloid is quite 'near its end, and consequently with a small paraboloidal rellector alone a comparativelysmall' burner could only be used. By referring to Fig. 1 this will at once be seen. 'By my invention, therefore, I-am enabled to use a compaia tively large burner with a medium-sized,

paraboloid, and thereby concentrate its rays Aof light to a greater degree than usual and project themfarthe'r into space. It a par; boloid were made su'lieently,larger than l) to receive the burner i at its .focus d, said paraboloid `would not, on account of its increased diaineter, concentrate the rays like l), and consequently their intensity would .be

' comparatively diminished.

A This im'cm.i."\n will prove highly valuzibl' ranged substantially :1S and f 01 Lne purposrf lmlocomotivc nml sl|ip1amps,m1.d will he also set forth. I

valuable fm,- siglml-lzunps. flint I claim'as new, and desire to secure i by Letters Patent, isi The cmnbilmton nf tlm` ellipsoilla-l and pmaboloidal reflectors El) nucl bunuel-01, nr

v NELSON J. KNAPP.

VVitnessesz' l y C. G. DAVISON, 

